Root Out
Shadows over Innistrad — Common
Sorcery
Root Out rulings:
2016-04-08: The token is named Clue Token and has the artifact subtype Clue. Clue isn't a creature type.
2016-04-08: The tokens are normal artifacts. For example, they can be sacrificed to cast Angelic Purge or targeted by Root Out.
2016-04-08: If you sacrifice a Clue for another card's cost or effect, such as that of Angelic Purge or Tamiyo's Journal, you can't also pay and sacrifice it to draw a card.
2016-04-08: You can't cast a spell without choosing legal targets. If all of those targets become illegal, the spell doesn't resolve and you won't investigate.
